JPH068007A - Rotary guide bush drive device - Google Patents

Abstract

PURPOSE:To rotate a guide bush at high speed by connecting a special motor to the guide bush and synchronizing it with a spindle. CONSTITUTION:An NC device outputs a rotation command signal to a spindle motor amplifier and a guide bush drive motor amplifier and drives a spindle motor 14 and a guide bush drive motor 23. Consequently, a spindle 12 and a guide bush 21 are cynchronized with each other and are rotated. The rotation command signal to the spindle motor amplifier and the guide bush drive motor amplifier at this time is specified to synchronously rotate the spindle 12 and the guide bush 21 at the same speed. Consequently, in the state where the spindle 12 and the guide bush 21 are synchronously rotated and a work W is held by the guide bush 21, the neighbourhood of the guide bush 21 is machined by a cutting tool.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary guide bush drive device for driving a rotatable guide bush provided on a main shaft moving type lathe.

Conventionally, in a lathe of a type in which a spindle holding a work moves in its axial direction, a rotatable guide bush having a guide hole for allowing the work to penetrate is provided in front of the spindle, and the work is processed by the guide bush. There is known a structure configured to hold the vicinity of the position. As the guide bush, there are one that simply rotates as the workpiece rotates and one that is forcedly rotated in synchronization with the main shaft.

Conventionally, as a means for rotating the guide bush in synchronism with the main shaft, as disclosed in Japanese Patent Application Laid-Open No. 56-119304, the outer periphery of the press nut of the collet chuck of the main shaft is parallel to the center axis of the main shaft. A guide groove is formed, and a tubular member is fixed to a sleeve that holds the guide bush, and an engaging member that slides in the guide groove is attached to the inner surface of the tubular member. There is known a structure in which the rotation of the main shaft is transmitted to the guide bush regardless of the position of the main shaft.

Further, as shown in FIG. 3, a spline shaft 2 is provided in parallel with a main shaft 1 for holding a work W, and a moving gear 3 is provided on the spline shaft 2 so as to be movable in the axial direction. Engagement, the moving gear 3 is connected to the headstock 6 via the bracket 5 so as to be movable together with the headstock 6, and further the gear 7 provided on the spline shaft 2 is engaged with the gear 9 provided on the guide bush 8. It is also known that the rotation of the main shaft 1 is transmitted to the spline shaft 2 by the gears 4 and 3, and then transmitted to the guide bush by the gears 7 and 9.

[0005]

However, all of the conventional guide bush drive mechanisms have problems. That is, the one disclosed in JP-A-56-119304 has a problem that the moving stroke of the main shaft cannot be increased because the cylindrical member attached to the guide bush covers the main shaft. Further, in the structure shown in FIG. 3, it is possible to increase the movement stroke of the main shaft by lengthening the spline shaft 2, but the inertia of the power transmission member between the main shaft 1 and the guide bush 8 is large. Therefore, there is a problem that it consumes extra energy and is not suitable for high speed rotation.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a drive device for a rotary guide bush which is not limited in the movement stroke of the main shaft and is suitable for high speed rotation.

[0007]

In order to solve the above problems, the present invention connects a guide bush with a motor dedicated to driving the guide bush so that the guide bush rotates in synchronization with the main shaft. , Is configured to be controlled by the control device.

As described above, the present invention has a structure in which a dedicated motor is drivingly connected to the guide bush and controls it, so that the guide bush can be rotationally driven in electrical synchronization with the main shaft. Unlike the conventional mechanism that mechanically synchronizes, there is no limitation on the movement stroke of the spindle, and since the inertia is not large, it is suitable for high speed rotation.

[0009]

FIG. 1 is a schematic configuration diagram of a preferred embodiment of the present invention, in which W is a work, 12 is a spindle that holds and rotates the work W, and 13 is a headstock that rotatably holds a spindle 12. , 14 are spindle motors for rotating the spindle 12.
The spindle motor 14 is not limited to the one provided outside the spindle stock 13 as in the illustrated embodiment, but may be a built-in mote housed in the spindle stock. A Z-axis slide 16 holds the headstock 13 and is held by a bed 17 so as to be movable in the main-axis direction (Z-axis direction).
18 is a screw shaft for moving the Z-axis slide 16, 1
Reference numeral 9 is a Z-axis servomotor that rotationally drives the screw shaft 18.

20 is a guide bush support, and 21 is
The guide bush is rotatably held by the guide bush support 20 in front of the main shaft 12, and has a guide hole through which the work W held by the main shaft 12 passes. 23
Is a guide bush drive motor attached to the guide bush support 20, 24 is a pulley attached to the rotating shaft of the guide bush drive motor, 25 is a pulley attached to the guide bush 21, and 26 is a pulley 24, 25. It is a belt. Reference numeral 28 denotes a control device for controlling the spindle motor 14 and the guide bush drive motor 23 so as to synchronize them, and as shown in FIG.
An NC device 30, a spindle motor amplifier 31, a guide bush drive motor amplifier 32, etc. are provided.

Next, the operation of the main shaft moving type lathe having the above structure will be described. The NC device 30 outputs a rotation command signal to the spindle motor amplifier 31 and the guide bush drive motor amplifier 32, and the spindle motor 14 and the guide bush drive motor 23.
To drive. As a result, the main shaft 12 and the guide bush 21 rotate in synchronization. Spindle motor amplifier 3 at this time
1. The rotation command signal to the guide bush drive motor amplifier 32 is set so that the spindle 12 and the guide bush 21 rotate synchronously at the same speed. Thus, spindle 1
2 and the guide bush 21 rotate synchronously, and the workpiece W is held by the guide bush 21, and the vicinity of the guide bush is processed by a blade (not shown).

In the above embodiment, the open loop system control for synchronously rotating the spindle 12 and the guide bush 21 is performed only by the rotation command signal from the NC device 30 to the spindle motor amplifier 31 and the guide bush drive motor amplifier 32. However, the present invention is not limited to this configuration,
The actual rotation speeds of the main shaft 12 and the guide bush 21 may be detected and fed back. Further, instead of supplying a rotation command to the guide bush drive motor 23 from the NC device 30, the rotation of the spindle 12 is detected and the guide bush drive motor 23 is detected according to the detected value.
May be driven.

[0013]

As described above, in the present invention, the guide bush is connected to the dedicated motor to rotate in synchronization with the main shaft. Therefore, the guide bush is rotated in electrical synchronization with the main shaft. It can be driven, and there is no need to mechanically connect the spindle to the guide bush, so there is no restriction on the stroke of movement of the spindle, and the inertia of the guide bush and related members is not large, so high-speed rotation is possible. It is possible to perform the above, and it has the effect of enabling high-speed cutting.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a spindle moving type lathe equipped with a rotation guide bush drive device according to a preferred embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control device in the above embodiment.

FIG. 3 is a schematic configuration diagram showing a spindle moving type lathe equipped with a conventional guide bush drive device.

[Explanation of symbols]

 W work 12 spindle 13 spindle headstock 14 spindle motor 16 Z-axis slide 17 bed 19 Z-axis servo motor 20 guide bush support 21 guide bush 23 guide bush drive motor 28 controller

Claims (1)

[Claims] 1. A lathe having a main shaft which holds a work and is movable in the axial direction, and a rotatable guide bush which is arranged at a fixed position in front of the main shaft and has a guide hole through which the work passes. A rotary guide bush drive device, comprising: a motor drivingly connected to the guide bush; and a control device for controlling the motor so as to rotate the guide bush in synchronization with the main shaft.